Aubergine fruit showing rot

After early concern about moneymaker aubergines when leaves were wilting they seemed to recover and thrive. Dozens of flowers and then fruit formed. Most still look good but found some had rotted, just on one side where flower hadn't detached. Spent hours looking up infections, diseases and other problems. Could be anything from potentially fatal virus infection to environmental problems. Certainly recent weather, heat and rain has provided the conditions that can cause the rot and I think the plants are a bit crowded reducing ventilation so humidity may be the cause. Fingers crossed. If it's worse not sure what I can do. Who'd be a gardener?